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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Shared Memory Communications over RDMA (SMC-R) and RoCE
4 *
5 * IB infrastructure:
6 * Establish SMC-R as an Infiniband Client to be notified about added and
7 * removed IB devices of type RDMA.
8 * Determine device and port characteristics for these IB devices.
9 *
10 * Copyright IBM Corp. 2016
11 *
12 * Author(s): Ursula Braun <ubraun@linux.vnet.ibm.com>
13 */
14
15#include <linux/random.h>
16#include <linux/workqueue.h>
17#include <linux/scatterlist.h>
18#include <rdma/ib_verbs.h>
19#include <rdma/ib_cache.h>
20
21#include "smc_pnet.h"
22#include "smc_ib.h"
23#include "smc_core.h"
24#include "smc_wr.h"
25#include "smc.h"
26
27#define SMC_MAX_CQE 32766 /* max. # of completion queue elements */
28
29#define SMC_QP_MIN_RNR_TIMER 5
30#define SMC_QP_TIMEOUT 15 /* 4096 * 2 ** timeout usec */
31#define SMC_QP_RETRY_CNT 7 /* 7: infinite */
32#define SMC_QP_RNR_RETRY 7 /* 7: infinite */
33
34struct smc_ib_devices smc_ib_devices = { /* smc-registered ib devices */
35 .lock = __SPIN_LOCK_UNLOCKED(smc_ib_devices.lock),
36 .list = LIST_HEAD_INIT(smc_ib_devices.list),
37};
38
39#define SMC_LOCAL_SYSTEMID_RESET "%%%%%%%"
40
41u8 local_systemid[SMC_SYSTEMID_LEN] = SMC_LOCAL_SYSTEMID_RESET; /* unique system
42 * identifier
43 */
44
45static int smc_ib_modify_qp_init(struct smc_link *lnk)
46{
47 struct ib_qp_attr qp_attr;
48
49 memset(&qp_attr, 0, sizeof(qp_attr));
50 qp_attr.qp_state = IB_QPS_INIT;
51 qp_attr.pkey_index = 0;
52 qp_attr.port_num = lnk->ibport;
53 qp_attr.qp_access_flags = IB_ACCESS_LOCAL_WRITE
54 | IB_ACCESS_REMOTE_WRITE;
55 return ib_modify_qp(lnk->roce_qp, &qp_attr,
56 IB_QP_STATE | IB_QP_PKEY_INDEX |
57 IB_QP_ACCESS_FLAGS | IB_QP_PORT);
58}
59
60static int smc_ib_modify_qp_rtr(struct smc_link *lnk)
61{
62 enum ib_qp_attr_mask qp_attr_mask =
63 IB_QP_STATE | IB_QP_AV | IB_QP_PATH_MTU | IB_QP_DEST_QPN |
64 IB_QP_RQ_PSN | IB_QP_MAX_DEST_RD_ATOMIC | IB_QP_MIN_RNR_TIMER;
65 struct ib_qp_attr qp_attr;
66
67 memset(&qp_attr, 0, sizeof(qp_attr));
68 qp_attr.qp_state = IB_QPS_RTR;
69 qp_attr.path_mtu = min(lnk->path_mtu, lnk->peer_mtu);
70 qp_attr.ah_attr.type = RDMA_AH_ATTR_TYPE_ROCE;
71 rdma_ah_set_port_num(&qp_attr.ah_attr, lnk->ibport);
72 rdma_ah_set_grh(&qp_attr.ah_attr, NULL, 0, lnk->sgid_index, 1, 0);
73 rdma_ah_set_dgid_raw(&qp_attr.ah_attr, lnk->peer_gid);
74 memcpy(&qp_attr.ah_attr.roce.dmac, lnk->peer_mac,
75 sizeof(lnk->peer_mac));
76 qp_attr.dest_qp_num = lnk->peer_qpn;
77 qp_attr.rq_psn = lnk->peer_psn; /* starting receive packet seq # */
78 qp_attr.max_dest_rd_atomic = 1; /* max # of resources for incoming
79 * requests
80 */
81 qp_attr.min_rnr_timer = SMC_QP_MIN_RNR_TIMER;
82
83 return ib_modify_qp(lnk->roce_qp, &qp_attr, qp_attr_mask);
84}
85
86int smc_ib_modify_qp_rts(struct smc_link *lnk)
87{
88 struct ib_qp_attr qp_attr;
89
90 memset(&qp_attr, 0, sizeof(qp_attr));
91 qp_attr.qp_state = IB_QPS_RTS;
92 qp_attr.timeout = SMC_QP_TIMEOUT; /* local ack timeout */
93 qp_attr.retry_cnt = SMC_QP_RETRY_CNT; /* retry count */
94 qp_attr.rnr_retry = SMC_QP_RNR_RETRY; /* RNR retries, 7=infinite */
95 qp_attr.sq_psn = lnk->psn_initial; /* starting send packet seq # */
96 qp_attr.max_rd_atomic = 1; /* # of outstanding RDMA reads and
97 * atomic ops allowed
98 */
99 return ib_modify_qp(lnk->roce_qp, &qp_attr,
100 IB_QP_STATE | IB_QP_TIMEOUT | IB_QP_RETRY_CNT |
101 IB_QP_SQ_PSN | IB_QP_RNR_RETRY |
102 IB_QP_MAX_QP_RD_ATOMIC);
103}
104
105int smc_ib_modify_qp_reset(struct smc_link *lnk)
106{
107 struct ib_qp_attr qp_attr;
108
109 memset(&qp_attr, 0, sizeof(qp_attr));
110 qp_attr.qp_state = IB_QPS_RESET;
111 return ib_modify_qp(lnk->roce_qp, &qp_attr, IB_QP_STATE);
112}
113
114int smc_ib_ready_link(struct smc_link *lnk)
115{
116 struct smc_link_group *lgr = smc_get_lgr(lnk);
117 int rc = 0;
118
119 rc = smc_ib_modify_qp_init(lnk);
120 if (rc)
121 goto out;
122
123 rc = smc_ib_modify_qp_rtr(lnk);
124 if (rc)
125 goto out;
126 smc_wr_remember_qp_attr(lnk);
127 rc = ib_req_notify_cq(lnk->smcibdev->roce_cq_recv,
128 IB_CQ_SOLICITED_MASK);
129 if (rc)
130 goto out;
131 rc = smc_wr_rx_post_init(lnk);
132 if (rc)
133 goto out;
134 smc_wr_remember_qp_attr(lnk);
135
136 if (lgr->role == SMC_SERV) {
137 rc = smc_ib_modify_qp_rts(lnk);
138 if (rc)
139 goto out;
140 smc_wr_remember_qp_attr(lnk);
141 }
142out:
143 return rc;
144}
145
146static int smc_ib_fill_mac(struct smc_ib_device *smcibdev, u8 ibport)
147{
148 const struct ib_gid_attr *attr;
149 int rc;
150
151 attr = rdma_get_gid_attr(smcibdev->ibdev, ibport, 0);
152 if (IS_ERR(attr))
153 return -ENODEV;
154
155 rc = rdma_read_gid_l2_fields(attr, NULL, smcibdev->mac[ibport - 1]);
156 rdma_put_gid_attr(attr);
157 return rc;
158}
159
160/* Create an identifier unique for this instance of SMC-R.
161 * The MAC-address of the first active registered IB device
162 * plus a random 2-byte number is used to create this identifier.
163 * This name is delivered to the peer during connection initialization.
164 */
165static inline void smc_ib_define_local_systemid(struct smc_ib_device *smcibdev,
166 u8 ibport)
167{
168 memcpy(&local_systemid[2], &smcibdev->mac[ibport - 1],
169 sizeof(smcibdev->mac[ibport - 1]));
170 get_random_bytes(&local_systemid[0], 2);
171}
172
173bool smc_ib_port_active(struct smc_ib_device *smcibdev, u8 ibport)
174{
175 return smcibdev->pattr[ibport - 1].state == IB_PORT_ACTIVE;
176}
177
178/* determine the gid for an ib-device port and vlan id */
179int smc_ib_determine_gid(struct smc_ib_device *smcibdev, u8 ibport,
180 unsigned short vlan_id, u8 gid[], u8 *sgid_index)
181{
182 const struct ib_gid_attr *attr;
183 const struct net_device *ndev;
184 int i;
185
186 for (i = 0; i < smcibdev->pattr[ibport - 1].gid_tbl_len; i++) {
187 attr = rdma_get_gid_attr(smcibdev->ibdev, ibport, i);
188 if (IS_ERR(attr))
189 continue;
190
191 rcu_read_lock();
192 ndev = rdma_read_gid_attr_ndev_rcu(attr);
193 if (!IS_ERR(ndev) &&
194 ((!vlan_id && !is_vlan_dev(attr->ndev)) ||
195 (vlan_id && is_vlan_dev(attr->ndev) &&
196 vlan_dev_vlan_id(attr->ndev) == vlan_id)) &&
197 attr->gid_type == IB_GID_TYPE_ROCE) {
198 rcu_read_unlock();
199 if (gid)
200 memcpy(gid, &attr->gid, SMC_GID_SIZE);
201 if (sgid_index)
202 *sgid_index = attr->index;
203 rdma_put_gid_attr(attr);
204 return 0;
205 }
206 rcu_read_unlock();
207 rdma_put_gid_attr(attr);
208 }
209 return -ENODEV;
210}
211
212static int smc_ib_remember_port_attr(struct smc_ib_device *smcibdev, u8 ibport)
213{
214 int rc;
215
216 memset(&smcibdev->pattr[ibport - 1], 0,
217 sizeof(smcibdev->pattr[ibport - 1]));
218 rc = ib_query_port(smcibdev->ibdev, ibport,
219 &smcibdev->pattr[ibport - 1]);
220 if (rc)
221 goto out;
222 /* the SMC protocol requires specification of the RoCE MAC address */
223 rc = smc_ib_fill_mac(smcibdev, ibport);
224 if (rc)
225 goto out;
226 if (!strncmp(local_systemid, SMC_LOCAL_SYSTEMID_RESET,
227 sizeof(local_systemid)) &&
228 smc_ib_port_active(smcibdev, ibport))
229 /* create unique system identifier */
230 smc_ib_define_local_systemid(smcibdev, ibport);
231out:
232 return rc;
233}
234
235/* process context wrapper for might_sleep smc_ib_remember_port_attr */
236static void smc_ib_port_event_work(struct work_struct *work)
237{
238 struct smc_ib_device *smcibdev = container_of(
239 work, struct smc_ib_device, port_event_work);
240 u8 port_idx;
241
242 for_each_set_bit(port_idx, &smcibdev->port_event_mask, SMC_MAX_PORTS) {
243 smc_ib_remember_port_attr(smcibdev, port_idx + 1);
244 clear_bit(port_idx, &smcibdev->port_event_mask);
245 if (!smc_ib_port_active(smcibdev, port_idx + 1))
246 smc_port_terminate(smcibdev, port_idx + 1);
247 }
248}
249
250/* can be called in IRQ context */
251static void smc_ib_global_event_handler(struct ib_event_handler *handler,
252 struct ib_event *ibevent)
253{
254 struct smc_ib_device *smcibdev;
255 u8 port_idx;
256
257 smcibdev = container_of(handler, struct smc_ib_device, event_handler);
258
259 switch (ibevent->event) {
260 case IB_EVENT_DEVICE_FATAL:
261 /* terminate all ports on device */
262 for (port_idx = 0; port_idx < SMC_MAX_PORTS; port_idx++)
263 set_bit(port_idx, &smcibdev->port_event_mask);
264 schedule_work(&smcibdev->port_event_work);
265 break;
266 case IB_EVENT_PORT_ERR:
267 case IB_EVENT_PORT_ACTIVE:
268 case IB_EVENT_GID_CHANGE:
269 port_idx = ibevent->element.port_num - 1;
270 if (port_idx < SMC_MAX_PORTS) {
271 set_bit(port_idx, &smcibdev->port_event_mask);
272 schedule_work(&smcibdev->port_event_work);
273 }
274 break;
275 default:
276 break;
277 }
278}
279
280void smc_ib_dealloc_protection_domain(struct smc_link *lnk)
281{
282 if (lnk->roce_pd)
283 ib_dealloc_pd(lnk->roce_pd);
284 lnk->roce_pd = NULL;
285}
286
287int smc_ib_create_protection_domain(struct smc_link *lnk)
288{
289 int rc;
290
291 lnk->roce_pd = ib_alloc_pd(lnk->smcibdev->ibdev, 0);
292 rc = PTR_ERR_OR_ZERO(lnk->roce_pd);
293 if (IS_ERR(lnk->roce_pd))
294 lnk->roce_pd = NULL;
295 return rc;
296}
297
298static void smc_ib_qp_event_handler(struct ib_event *ibevent, void *priv)
299{
300 struct smc_link *lnk = (struct smc_link *)priv;
301 struct smc_ib_device *smcibdev = lnk->smcibdev;
302 u8 port_idx;
303
304 switch (ibevent->event) {
305 case IB_EVENT_QP_FATAL:
306 case IB_EVENT_QP_ACCESS_ERR:
307 port_idx = ibevent->element.qp->port - 1;
308 if (port_idx < SMC_MAX_PORTS) {
309 set_bit(port_idx, &smcibdev->port_event_mask);
310 schedule_work(&smcibdev->port_event_work);
311 }
312 break;
313 default:
314 break;
315 }
316}
317
318void smc_ib_destroy_queue_pair(struct smc_link *lnk)
319{
320 if (lnk->roce_qp)
321 ib_destroy_qp(lnk->roce_qp);
322 lnk->roce_qp = NULL;
323}
324
325/* create a queue pair within the protection domain for a link */
326int smc_ib_create_queue_pair(struct smc_link *lnk)
327{
328 struct ib_qp_init_attr qp_attr = {
329 .event_handler = smc_ib_qp_event_handler,
330 .qp_context = lnk,
331 .send_cq = lnk->smcibdev->roce_cq_send,
332 .recv_cq = lnk->smcibdev->roce_cq_recv,
333 .srq = NULL,
334 .cap = {
335 /* include unsolicited rdma_writes as well,
336 * there are max. 2 RDMA_WRITE per 1 WR_SEND
337 */
338 .max_send_wr = SMC_WR_BUF_CNT * 3,
339 .max_recv_wr = SMC_WR_BUF_CNT * 3,
340 .max_send_sge = SMC_IB_MAX_SEND_SGE,
341 .max_recv_sge = 1,
342 },
343 .sq_sig_type = IB_SIGNAL_REQ_WR,
344 .qp_type = IB_QPT_RC,
345 };
346 int rc;
347
348 lnk->roce_qp = ib_create_qp(lnk->roce_pd, &qp_attr);
349 rc = PTR_ERR_OR_ZERO(lnk->roce_qp);
350 if (IS_ERR(lnk->roce_qp))
351 lnk->roce_qp = NULL;
352 else
353 smc_wr_remember_qp_attr(lnk);
354 return rc;
355}
356
357void smc_ib_put_memory_region(struct ib_mr *mr)
358{
359 ib_dereg_mr(mr);
360}
361
362static int smc_ib_map_mr_sg(struct smc_buf_desc *buf_slot)
363{
364 unsigned int offset = 0;
365 int sg_num;
366
367 /* map the largest prefix of a dma mapped SG list */
368 sg_num = ib_map_mr_sg(buf_slot->mr_rx[SMC_SINGLE_LINK],
369 buf_slot->sgt[SMC_SINGLE_LINK].sgl,
370 buf_slot->sgt[SMC_SINGLE_LINK].orig_nents,
371 &offset, PAGE_SIZE);
372
373 return sg_num;
374}
375
376/* Allocate a memory region and map the dma mapped SG list of buf_slot */
377int smc_ib_get_memory_region(struct ib_pd *pd, int access_flags,
378 struct smc_buf_desc *buf_slot)
379{
380 if (buf_slot->mr_rx[SMC_SINGLE_LINK])
381 return 0; /* already done */
382
383 buf_slot->mr_rx[SMC_SINGLE_LINK] =
384 ib_alloc_mr(pd, IB_MR_TYPE_MEM_REG, 1 << buf_slot->order);
385 if (IS_ERR(buf_slot->mr_rx[SMC_SINGLE_LINK])) {
386 int rc;
387
388 rc = PTR_ERR(buf_slot->mr_rx[SMC_SINGLE_LINK]);
389 buf_slot->mr_rx[SMC_SINGLE_LINK] = NULL;
390 return rc;
391 }
392
393 if (smc_ib_map_mr_sg(buf_slot) != 1)
394 return -EINVAL;
395
396 return 0;
397}
398
399/* synchronize buffer usage for cpu access */
400void smc_ib_sync_sg_for_cpu(struct smc_ib_device *smcibdev,
401 struct smc_buf_desc *buf_slot,
402 enum dma_data_direction data_direction)
403{
404 struct scatterlist *sg;
405 unsigned int i;
406
407 /* for now there is just one DMA address */
408 for_each_sg(buf_slot->sgt[SMC_SINGLE_LINK].sgl, sg,
409 buf_slot->sgt[SMC_SINGLE_LINK].nents, i) {
410 if (!sg_dma_len(sg))
411 break;
412 ib_dma_sync_single_for_cpu(smcibdev->ibdev,
413 sg_dma_address(sg),
414 sg_dma_len(sg),
415 data_direction);
416 }
417}
418
419/* synchronize buffer usage for device access */
420void smc_ib_sync_sg_for_device(struct smc_ib_device *smcibdev,
421 struct smc_buf_desc *buf_slot,
422 enum dma_data_direction data_direction)
423{
424 struct scatterlist *sg;
425 unsigned int i;
426
427 /* for now there is just one DMA address */
428 for_each_sg(buf_slot->sgt[SMC_SINGLE_LINK].sgl, sg,
429 buf_slot->sgt[SMC_SINGLE_LINK].nents, i) {
430 if (!sg_dma_len(sg))
431 break;
432 ib_dma_sync_single_for_device(smcibdev->ibdev,
433 sg_dma_address(sg),
434 sg_dma_len(sg),
435 data_direction);
436 }
437}
438
439/* Map a new TX or RX buffer SG-table to DMA */
440int smc_ib_buf_map_sg(struct smc_ib_device *smcibdev,
441 struct smc_buf_desc *buf_slot,
442 enum dma_data_direction data_direction)
443{
444 int mapped_nents;
445
446 mapped_nents = ib_dma_map_sg(smcibdev->ibdev,
447 buf_slot->sgt[SMC_SINGLE_LINK].sgl,
448 buf_slot->sgt[SMC_SINGLE_LINK].orig_nents,
449 data_direction);
450 if (!mapped_nents)
451 return -ENOMEM;
452
453 return mapped_nents;
454}
455
456void smc_ib_buf_unmap_sg(struct smc_ib_device *smcibdev,
457 struct smc_buf_desc *buf_slot,
458 enum dma_data_direction data_direction)
459{
460 if (!buf_slot->sgt[SMC_SINGLE_LINK].sgl->dma_address)
461 return; /* already unmapped */
462
463 ib_dma_unmap_sg(smcibdev->ibdev,
464 buf_slot->sgt[SMC_SINGLE_LINK].sgl,
465 buf_slot->sgt[SMC_SINGLE_LINK].orig_nents,
466 data_direction);
467 buf_slot->sgt[SMC_SINGLE_LINK].sgl->dma_address = 0;
468}
469
470long smc_ib_setup_per_ibdev(struct smc_ib_device *smcibdev)
471{
472 struct ib_cq_init_attr cqattr = {
473 .cqe = SMC_MAX_CQE, .comp_vector = 0 };
474 int cqe_size_order, smc_order;
475 long rc;
476
477 /* the calculated number of cq entries fits to mlx5 cq allocation */
478 cqe_size_order = cache_line_size() == 128 ? 7 : 6;
479 smc_order = MAX_ORDER - cqe_size_order - 1;
480 if (SMC_MAX_CQE + 2 > (0x00000001 << smc_order) * PAGE_SIZE)
481 cqattr.cqe = (0x00000001 << smc_order) * PAGE_SIZE - 2;
482 smcibdev->roce_cq_send = ib_create_cq(smcibdev->ibdev,
483 smc_wr_tx_cq_handler, NULL,
484 smcibdev, &cqattr);
485 rc = PTR_ERR_OR_ZERO(smcibdev->roce_cq_send);
486 if (IS_ERR(smcibdev->roce_cq_send)) {
487 smcibdev->roce_cq_send = NULL;
488 return rc;
489 }
490 smcibdev->roce_cq_recv = ib_create_cq(smcibdev->ibdev,
491 smc_wr_rx_cq_handler, NULL,
492 smcibdev, &cqattr);
493 rc = PTR_ERR_OR_ZERO(smcibdev->roce_cq_recv);
494 if (IS_ERR(smcibdev->roce_cq_recv)) {
495 smcibdev->roce_cq_recv = NULL;
496 goto err;
497 }
498 smc_wr_add_dev(smcibdev);
499 smcibdev->initialized = 1;
500 return rc;
501
502err:
503 ib_destroy_cq(smcibdev->roce_cq_send);
504 return rc;
505}
506
507static void smc_ib_cleanup_per_ibdev(struct smc_ib_device *smcibdev)
508{
509 if (!smcibdev->initialized)
510 return;
511 smcibdev->initialized = 0;
512 smc_wr_remove_dev(smcibdev);
513 ib_destroy_cq(smcibdev->roce_cq_recv);
514 ib_destroy_cq(smcibdev->roce_cq_send);
515}
516
517static struct ib_client smc_ib_client;
518
519/* callback function for ib_register_client() */
520static void smc_ib_add_dev(struct ib_device *ibdev)
521{
522 struct smc_ib_device *smcibdev;
523 u8 port_cnt;
524 int i;
525
526 if (ibdev->node_type != RDMA_NODE_IB_CA)
527 return;
528
529 smcibdev = kzalloc(sizeof(*smcibdev), GFP_KERNEL);
530 if (!smcibdev)
531 return;
532
533 smcibdev->ibdev = ibdev;
534 INIT_WORK(&smcibdev->port_event_work, smc_ib_port_event_work);
535
536 spin_lock(&smc_ib_devices.lock);
537 list_add_tail(&smcibdev->list, &smc_ib_devices.list);
538 spin_unlock(&smc_ib_devices.lock);
539 ib_set_client_data(ibdev, &smc_ib_client, smcibdev);
540 INIT_IB_EVENT_HANDLER(&smcibdev->event_handler, smcibdev->ibdev,
541 smc_ib_global_event_handler);
542 ib_register_event_handler(&smcibdev->event_handler);
543
544 /* trigger reading of the port attributes */
545 port_cnt = smcibdev->ibdev->phys_port_cnt;
546 for (i = 0;
547 i < min_t(size_t, port_cnt, SMC_MAX_PORTS);
548 i++) {
549 set_bit(i, &smcibdev->port_event_mask);
550 /* determine pnetids of the port */
551 smc_pnetid_by_dev_port(ibdev->dev.parent, i,
552 smcibdev->pnetid[i]);
553 }
554 schedule_work(&smcibdev->port_event_work);
555}
556
557/* callback function for ib_register_client() */
558static void smc_ib_remove_dev(struct ib_device *ibdev, void *client_data)
559{
560 struct smc_ib_device *smcibdev;
561
562 smcibdev = ib_get_client_data(ibdev, &smc_ib_client);
563 ib_set_client_data(ibdev, &smc_ib_client, NULL);
564 spin_lock(&smc_ib_devices.lock);
565 list_del_init(&smcibdev->list); /* remove from smc_ib_devices */
566 spin_unlock(&smc_ib_devices.lock);
567 smc_ib_cleanup_per_ibdev(smcibdev);
568 ib_unregister_event_handler(&smcibdev->event_handler);
569 kfree(smcibdev);
570}
571
572static struct ib_client smc_ib_client = {
573 .name = "smc_ib",
574 .add = smc_ib_add_dev,
575 .remove = smc_ib_remove_dev,
576};
577
578int __init smc_ib_register_client(void)
579{
580 return ib_register_client(&smc_ib_client);
581}
582
583void smc_ib_unregister_client(void)
584{
585 ib_unregister_client(&smc_ib_client);
586}